This application claims the priority of Japanese Patent Application No. 2004-025728 filed on Feb. 2, 2004, the specification, drawings and abstract thereof, are incorporated herein by reference in their entirety.
1. Field of the Invention
The present invention relates to a drive-control-system of an electromotive vehicle and a drive-control-method of the electromotive vehicle.
2. Description of the Related Art
Conventionally, a vehicle-drive-system mounted on a hybrid vehicle such as an electromotive vehicle, in which a part of engine-torque, that is torque of an engine is transmitted to a generator (generator motor) and the rest of the engine torque is transmitted to a driving wheel, has a planetary gear unit as a differential tuning gear having a sun gear, ring gear, and carrier. The sun gear is linked with the generator, the ring gear and a driving motor are linked with the driving wheel, the carrier is linked with the engine, and rotation outputted from the ring gear and the driving motor is transmitted to the driving wheel to generate driving force.
In the vehicle-drive-system, an inverter is arranged between the driving motor and a driving-motor-control-system. The inverter, which is driven according to a driving signal sent from the driving-motor-control-system, receives DC electric current from a battery, generates electric current in U phase, V phase and W phase, and provides the electric current in each phase to the driving motor. Thus, the inverter has a plurality of, for example, six transistors, as switching elements. The transistors are unitized by pairs to form transistor modules, Insulated Gate Bipolar Transistor (IGBT), in respective phases. Therefore, when the driving signal is sent to each of the transistors in a predetermined pattern, the transistor is turned on and off, and generates the electric current in each phase.
Driving-motor-rotation-speed, which is a rotation speed of the driving motor, is detected by a driving-motor-rotation-speed sensor, and for example, driving-motor-torque, that is torque of the driving motor, is controlled based on the driving-motor-rotation-speed.
However, in the conventional vehicle-drive-system, (JP-A-2002-12046), for example, when driving torque generated in the driving wheel for running the hybrid vehicle varies, or the engine is started or stopped, vibration is generated in the vehicle-drive-system, resulting in discomfort to a driver. Therefore, damping control is performed, wherein driving-motor-torque of the driving motor is controlled such that the vibration in the vehicle-driving-system is damped. However, when the driving-motor-torque is controlled such that the vibration in the vehicle-driving-system is damped at any time, especially in steady running, high-frequency vibration is generated in a sensor output from a position sensor for detecting a rotor position of the driving motor due to noise, resulting in discomfort to the driver.
Thus, to suppress the high-frequency vibration generated simply due to the noise in the sensor output from the position sensor, it is determined that response in the damping control is lowered by reducing control gain in the damping control, removing the noise by passing the sensor output from the position sensor through a filter, or performing blunting to the sensor output. However, in this case, for example, when the driving torque varies, or the engine is started or stopped, the vibration generated in the vehicle-drive-system can not be quickly damped, resulting in discomfort to the driver.